Myectomy reduces ileal motility after ileoanal anastomosis.

The hypothesis tested was that myectomy of the distal ileum would produce a long-lasting decrease in ileal motility, and so render single-lumen ileum more suitable for use as a rectal substitute in the course of restorative proctocolectomy, without the need for a pelvic ileal reservoir. Ileal motility, both spontaneous and in response to intraluminal volatile fatty acids (VFA), was studied after proctocolectomy in 25 female adult beagles, at least 6 months after ileoanal anastomosis alone (IAA, n = 6), IAA with myectomy (n = 8), IAA with myectomy and an ileal valve (n = 5) or IAA with a duplicated (J) ileal reservoir (n = 6). VFA were found to stimulate ileal motility significantly in each group. Myectomy significantly reduced the number of ileal contractions (P less than 0.01), the mean amplitude of contractions (P less than 0.05) and the motility index (P less than 0.01). The addition of the valve to myectomy made no significant difference.